Updated version of the ltc2990 driver which supports all measurement modes available in the chip. The mode can be set through a devicetree attribute.
Signed-off-by: Tom Levens <[email protected]> --- Changes since v1: * Refactored value conversion (patch 1/3) * Split the devicetree binding into separate patch (patch 2/3) * Specifying an invalid mode now returns -EINVAL, previously this only issued a warning and used the default value * Removed the "mode" sysfs attribute, as the mode of the chip is hardware specific and should not be user configurable. This allows much simpler code as a result. Documentation/hwmon/ltc2990 | 24 ++++--- drivers/hwmon/Kconfig | 7 +-- drivers/hwmon/ltc2990.c | 167 ++++++++++++++++++++++++++++++++++++------- 3 files changed, 159 insertions(+), 39 deletions(-) diff --git a/Documentation/hwmon/ltc2990 b/Documentation/hwmon/ltc2990 index c25211e..3ed68f6 100644 --- a/Documentation/hwmon/ltc2990 +++ b/Documentation/hwmon/ltc2990 @@ -8,6 +8,7 @@ Supported chips: Datasheet: http://www.linear.com/product/ltc2990 Author: Mike Looijmans <[email protected]> + Tom Levens <[email protected]> Description @@ -16,10 +17,8 @@ Description LTC2990 is a Quad I2C Voltage, Current and Temperature Monitor. The chip's inputs can measure 4 voltages, or two inputs together (1+2 and 3+4) can be combined to measure a differential voltage, which is typically used to -measure current through a series resistor, or a temperature. - -This driver currently uses the 2x differential mode only. In order to support -other modes, the driver will need to be expanded. +measure current through a series resistor, or a temperature with an external +diode. Usage Notes @@ -32,12 +31,19 @@ devices explicitly. Sysfs attributes ---------------- +in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V) +temp1_input Internal chip temperature in millidegrees Celcius + +A subset of the following attributes are visible, depending on the measurement +mode of the chip. + +in[1-4]_input Voltage at V[1-4] pin in millivolt +temp2_input External temperature sensor TR1 in millidegrees Celcius +temp3_input External temperature sensor TR2 in millidegrees Celcius +curr1_input Current in mA across V1-V2 assuming a 1mOhm sense resistor +curr2_input Current in mA across V3-V4 assuming a 1mOhm sense resistor + The "curr*_input" measurements actually report the voltage drop across the input pins in microvolts. This is equivalent to the current through a 1mOhm sense resistor. Divide the reported value by the actual sense resistor value in mOhm to get the actual value. - -in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V) -temp1_input Internal chip temperature in millidegrees Celcius -curr1_input Current in mA across v1-v2 assuming a 1mOhm sense resistor. -curr2_input Current in mA across v3-v4 assuming a 1mOhm sense resistor. diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 45cef3d..f7096ca 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -699,15 +699,12 @@ config SENSORS_LTC2945 be called ltc2945. config SENSORS_LTC2990 - tristate "Linear Technology LTC2990 (current monitoring mode only)" + tristate "Linear Technology LTC2990" depends on I2C help If you say yes here you get support for Linear Technology LTC2990 I2C System Monitor. The LTC2990 supports a combination of voltage, - current and temperature monitoring, but in addition to the Vcc supply - voltage and chip temperature, this driver currently only supports - reading two currents by measuring two differential voltages across - series resistors. + current and temperature monitoring. This driver can also be built as a module. If so, the module will be called ltc2990. diff --git a/drivers/hwmon/ltc2990.c b/drivers/hwmon/ltc2990.c index 0ec4102..e8d36f5 100644 --- a/drivers/hwmon/ltc2990.c +++ b/drivers/hwmon/ltc2990.c @@ -6,11 +6,7 @@ * * License: GPLv2 * - * This driver assumes the chip is wired as a dual current monitor, and - * reports the voltage drop across two series resistors. It also reports - * the chip's internal temperature and Vcc power supply voltage. - * - * Value conversion refactored + * Value conversion refactored and support for all measurement modes added * by Tom Levens <[email protected]> */ @@ -21,6 +17,7 @@ #include <linux/i2c.h> #include <linux/kernel.h> #include <linux/module.h> +#include <linux/of.h> #define LTC2990_STATUS 0x00 #define LTC2990_CONTROL 0x01 @@ -35,32 +32,96 @@ #define LTC2990_CONTROL_KELVIN BIT(7) #define LTC2990_CONTROL_SINGLE BIT(6) #define LTC2990_CONTROL_MEASURE_ALL (0x3 << 3) -#define LTC2990_CONTROL_MODE_CURRENT 0x06 -#define LTC2990_CONTROL_MODE_VOLTAGE 0x07 +#define LTC2990_CONTROL_MODE_DEFAULT 0x06 +#define LTC2990_CONTROL_MODE_MAX 0x07 + +#define LTC2990_IN0 BIT(0) +#define LTC2990_IN1 BIT(1) +#define LTC2990_IN2 BIT(2) +#define LTC2990_IN3 BIT(3) +#define LTC2990_IN4 BIT(4) +#define LTC2990_CURR1 BIT(5) +#define LTC2990_CURR2 BIT(6) +#define LTC2990_TEMP1 BIT(7) +#define LTC2990_TEMP2 BIT(8) +#define LTC2990_TEMP3 BIT(9) + +static const int ltc2990_attrs_ena[] = { + LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3, + LTC2990_CURR1 | LTC2990_TEMP3, + LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4, + LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4, + LTC2990_TEMP2 | LTC2990_CURR2, + LTC2990_TEMP2 | LTC2990_TEMP3, + LTC2990_CURR1 | LTC2990_CURR2, + LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4 +}; + +struct ltc2990_data { + struct i2c_client *i2c; + u32 mode; +}; /* Return the converted value from the given register in uV or mC */ -static int ltc2990_get_value(struct i2c_client *i2c, u8 reg, s32 *result) +static int ltc2990_get_value(struct i2c_client *i2c, int index, s32 *result) { s32 val; + u8 reg; + + switch (index) { + case LTC2990_IN0: + reg = LTC2990_VCC_MSB; + break; + case LTC2990_IN1: + case LTC2990_CURR1: + case LTC2990_TEMP2: + reg = LTC2990_V1_MSB; + break; + case LTC2990_IN2: + reg = LTC2990_V2_MSB; + break; + case LTC2990_IN3: + case LTC2990_CURR2: + case LTC2990_TEMP3: + reg = LTC2990_V3_MSB; + break; + case LTC2990_IN4: + reg = LTC2990_V4_MSB; + break; + case LTC2990_TEMP1: + reg = LTC2990_TINT_MSB; + break; + default: + return -EINVAL; + } val = i2c_smbus_read_word_swapped(i2c, reg); if (unlikely(val < 0)) return val; - switch (reg) { - case LTC2990_TINT_MSB: - /* internal temp, 0.0625 degrees/LSB, 13-bit */ + switch (index) { + case LTC2990_TEMP1: + case LTC2990_TEMP2: + case LTC2990_TEMP3: + /* temp, 0.0625 degrees/LSB, 13-bit */ *result = sign_extend32(val, 12) * 1000 / 16; break; - case LTC2990_V1_MSB: - case LTC2990_V3_MSB: - /* Vx-Vy, 19.42uV/LSB. Depends on mode. */ + case LTC2990_CURR1: + case LTC2990_CURR2: + /* Vx-Vy, 19.42uV/LSB */ *result = sign_extend32(val, 14) * 1942 / 100; break; - case LTC2990_VCC_MSB: - /* Vcc, 305.18μV/LSB, 2.5V offset */ + case LTC2990_IN0: + /* Vcc, 305.18uV/LSB, 2.5V offset */ *result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500; break; + case LTC2990_IN1: + case LTC2990_IN2: + case LTC2990_IN3: + case LTC2990_IN4: + /* Vx: 305.18uV/LSB */ + *result = sign_extend32(val, 14) * 30518 / (100 * 1000); + break; default: return -EINVAL; /* won't happen, keep compiler happy */ } @@ -72,48 +133,104 @@ static ssize_t ltc2990_show_value(struct device *dev, struct device_attribute *da, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ltc2990_data *data = dev_get_drvdata(dev); s32 value; int ret; - ret = ltc2990_get_value(dev_get_drvdata(dev), attr->index, &value); + ret = ltc2990_get_value(data->i2c, attr->index, &value); if (unlikely(ret < 0)) return ret; return snprintf(buf, PAGE_SIZE, "%d\n", value); } +static umode_t ltc2990_attrs_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct ltc2990_data *data = dev_get_drvdata(dev); + struct device_attribute *da = + container_of(a, struct device_attribute, attr); + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + + if (attr->index == LTC2990_TEMP1 || + attr->index == LTC2990_IN0 || + attr->index & ltc2990_attrs_ena[data->mode]) + return a->mode; + else + return 0; +} + static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, ltc2990_show_value, NULL, - LTC2990_TINT_MSB); + LTC2990_TEMP1); +static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_TEMP2); +static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_TEMP3); static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc2990_show_value, NULL, - LTC2990_V1_MSB); + LTC2990_CURR1); static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ltc2990_show_value, NULL, - LTC2990_V3_MSB); + LTC2990_CURR2); static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ltc2990_show_value, NULL, - LTC2990_VCC_MSB); + LTC2990_IN0); +static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_IN1); +static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_IN2); +static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_IN3); +static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ltc2990_show_value, NULL, + LTC2990_IN4); static struct attribute *ltc2990_attrs[] = { &sensor_dev_attr_temp1_input.dev_attr.attr, + &sensor_dev_attr_temp2_input.dev_attr.attr, + &sensor_dev_attr_temp3_input.dev_attr.attr, &sensor_dev_attr_curr1_input.dev_attr.attr, &sensor_dev_attr_curr2_input.dev_attr.attr, &sensor_dev_attr_in0_input.dev_attr.attr, + &sensor_dev_attr_in1_input.dev_attr.attr, + &sensor_dev_attr_in2_input.dev_attr.attr, + &sensor_dev_attr_in3_input.dev_attr.attr, + &sensor_dev_attr_in4_input.dev_attr.attr, NULL, }; -ATTRIBUTE_GROUPS(ltc2990); + +static const struct attribute_group ltc2990_group = { + .attrs = ltc2990_attrs, + .is_visible = ltc2990_attrs_visible, +}; +__ATTRIBUTE_GROUPS(ltc2990); static int ltc2990_i2c_probe(struct i2c_client *i2c, const struct i2c_device_id *id) { int ret; struct device *hwmon_dev; + struct ltc2990_data *data; + struct device_node *of_node = i2c->dev.of_node; if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) return -ENODEV; - /* Setup continuous mode, current monitor */ + data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL); + if (unlikely(!data)) + return -ENOMEM; + data->i2c = i2c; + + if (!of_node || of_property_read_u32(of_node, "lltc,mode", &data->mode)) + data->mode = LTC2990_CONTROL_MODE_DEFAULT; + + if (data->mode > LTC2990_CONTROL_MODE_MAX) { + dev_err(&i2c->dev, "Error: Invalid mode %d.\n", data->mode); + return -EINVAL; + } + + /* Setup continuous mode */ ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL, LTC2990_CONTROL_MEASURE_ALL | - LTC2990_CONTROL_MODE_CURRENT); + data->mode); if (ret < 0) { dev_err(&i2c->dev, "Error: Failed to set control mode.\n"); return ret; @@ -127,7 +244,7 @@ static int ltc2990_i2c_probe(struct i2c_client *i2c, hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev, i2c->name, - i2c, + data, ltc2990_groups); return PTR_ERR_OR_ZERO(hwmon_dev); -- 1.7.1
